Simple hierarchical label-switched paths

ABSTRACT

A device may identify a portion of a label-switched path (LSP) on which a simple hierarchical LSP (sH-LSP) is to be used for transferring traffic via a network. The device may determine attribute information associated with the sH-LSP. The attribute information may include information associated with one or more characteristics of the sH-LSP. The device may provide an indication associated with identifying an available sH-LSP or creating a sH-LSP. The indication may include the attribute information associated with the sH-LSP, and may be being provided to cause the sH-LSP to be created on the portion of the LSP or an available sH-LSP, associated with the portion of the LSP, to be identified. The device may receive, based on providing the indication, an identifier associated with the sH-LSP. The device may cause the LSP to be set up based on the identifier associated with the sH-LSP.

BACKGROUND

A label-switched path (LSP) is a network path through a label switchingnetwork, such as a Multi-Protocol Label Switching (MPLS) network. TheLSP may begin at an ingress device located at an edge of the labelswitching network (e.g., a first label edge router (LER)), and mayinclude one or more intermediate network devices (e.g., one or morelabel switched routers (LSRs)) before ending at an egress device at theedge of the label switching network (e.g., a second LER).

SUMMARY

According to some possible implementations, a method may include:identifying, by a device, a portion of a label-switched path (LSP) onwhich a simple hierarchical LSP (sH-LSP) is to be used for transferringtraffic via a network; determining, by the device, attribute informationassociated with the sH-LSP, where the attribute information may includeinformation associated with one or more characteristics of the sH-LSP;providing, by the device, an indication associated with identifying anavailable sH-LSP or creating a sH-LSP, where the indication may includethe attribute information associated with the sH-LSP, and where theindication may be provided to cause the sH-LSP to be created on theportion of the LSP or an available sH-LSP, associated with the portionof the LSP, to be identified; receiving, by the device and based onproviding the indication, an identifier associated with the sH-LSP; andcausing, by the device, the LSP to be set up based on the identifierassociated with the sH-LSP.

According to some possible implementations, a device may include one ormore processors to: identify a portion of a label-switched path (LSP)for which a simple hierarchical LSP (sH-LSP) is to be used to transfertraffic across a network; determine attribute information associatedwith the sH-LSP, where the attribute information may identify one ormore characteristics of the sH-LSP; and provide information associatedwith setting up the LSP, where the information may include informationindicating that the sH-LSP is to be used on the portion of the LSP andthe attribute information associated with the sH-LSP, and where theinformation may be provided to cause the sH-LSP to be automaticallycreated on the portion of the LSP or to cause an available sH-LSP,existing on the portion of the LSP, to be identified.

According to some possible implementations, a method may include:receiving, by a device, an indication associated with a simplehierarchical label switched path (sH-LSP), where the sH-LSP may beassociated with a portion of a LSP, and where the indication may includeattribute information associated with the sH-LSP; determining, by thedevice, whether an existing sH-LSP, associated with the portion of theLSP, is available to be used on the portion of the LSP; selectively:creating the sH-LSP based on determining that the existing sH-LSP is notavailable to be used on the portion of the LSP, where the sH-LSP may becreated based on the attribute information, or identifying that theexisting sH-LSP is to be used on the portion of the LSP based ondetermining that the existing sH-LSP is available; and providing, by thedevice, an identifier associated with the created sH-LSP or anidentifier associated with the existing sH-LSP, where the identifier maybe provided to permit the LSP to be set up based on the identifier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1H are diagrams of an overview of an example implementationdescribed herein;

FIG. 2 is a diagram of an example environment in which systems and/ormethods, described herein, may be implemented;

FIGS. 3A and 3B are diagrams of example components of one or moredevices of FIG. 2;

FIG. 4 is a flow chart of an example process for providing anindication, associated with setting up a LSP, that includes anidentifier associated with a simple hierarchical LSP; and

FIG. 5 is a flow chart of an example process for providing anindication, associated with setting up a LSP, that includes attributeinformation associated with a simple hierarchical LSP.

DETAILED DESCRIPTION

The following detailed description of example implementations refers tothe accompanying drawings. The same reference numbers in differentdrawings may identify the same or similar elements.

Aggregating LSPs to create a hierarchy of LSPs may allow for improvedscalability of a label switching network (e.g., an MPLS network, aGeneralized MPLS (GMPLS) network, etc.). For example, creating ahierarchy of LSPs (e.g., such that an LSP includes a set of alabel-switched concatenation of physical interfaces and/or a set ofhierarchical LSPs (H-LSPs)), may allow for improved scalability of anMPLS network. One manner in which such a hierarchy may be created is byconfiguring a router (e.g., a LER, a LSR, etc.) to form an H-LSP whencreating a LSP by, for example, advertising the LSP as a TrafficEngineering (TE) link (e.g., on a same Interior Gateway Protocol (IGP)instance as an IGP instance that was used to create the LSP). The routermay then allow other routers to use the H-LSP for path computationand/or may nest other H-LSPs created by the other routers into the H-LSP(e.g., by using the label stack construct). As such, the H-LSP mayinclude a set of hierarchically next-lower H-LSPs where, at a lowestlayer, a hierarchy may include a set of label-switched sequences ofphysical interfaces (e.g., as with traditional LSPs). Similarly, theH-LSP may be included in a hierarchically next-higher H-LSP.

However, distributed management (e.g., deployment, configuration,maintenance, creation, etc.) of H-LSPs within the network may require asignificant amount of overhead within the network and/or by a user. Forexample, management of H-LSPs within the network may need to beconfigured on a per router basis. As such, due to the distributed natureof managing H-LSPs, it may not be possible for a centralized entity(e.g., a Path Computation Element (PCE)) to instruct a router to createan H-LSP, even though such instruction may simplify management of theH-LSP and/or an overlay LSP that includes the H-LSP.

Implementations described herein may provide for a simple H-LSP (sH-LSP)for which management is simplified such that an amount of resourcesand/or an amount of user configuration is reduced (e.g., as compared toa traditional H-LSP). In some implementations, a sH-LSP differs from atraditional H-LSP in that a centralized entity, such as a PCE, may causethe sH-LSP to be created (while is not possible for a centralized entityto cause a traditional H-LSP to be created). For example, the PCE mayindicate that the sH-LSP is to be used on a particular portion of a LSPassociated with a network and, thus, may instruct another device tocreate the sH-LSP or identify of an existing sH-LSP for use in the LSP.The sH-LSP also differs from the traditional H-LSP in that the sH-LSPmay be kept private (i.e., not advertised) such that only the PCE and ahead end node, associated with the sH-LSP, know of the existence of thesH-LSP (while existence of the traditional H-LSP may be advertised toother devices).

In some implementations, the PCE may cause the LSP to be set up afterthe PCE receives an identifier associated with the sH-LSP. In someimplementations, after the sH-LSP is created, the sH-LSP identifier(e.g., a TE link identifier) may be kept private (i.e., may notadvertised) such that only the PCE and/or a head end node of the sH-LSPstore or have access to the sH-LSP identifier. This may prevent overuseand/or congestion of the sH-LSP since the PCE may monitor and/or manageuse of the sH-LSP for various traffic flows. In some implementations,the PCE may cause the LSP to be set up based on providing attributeinformation associated with the sH-LSP (e.g., such that the sH-LSP iscreated or identified during setup of the LSP).

FIGS. 1A-1H are diagrams of an overview of example implementations 100and 150 described herein. For the purposes of example implementations100 and 150, assume that a PCE has received an indication to initiatesetup of a LSP for transferring traffic between a first edge device of afirst network (e.g., ND1 in network 1) and a second edge device of asecond network (e.g., ND12 in network 2). Further, assume that the PCEis configured to identify one or more portions of the LSP on whichsH-LSPs are to be used when setting up the LSP.

A sH-LSP may include an H-LSP that is automatically (e.g., without userintervention) and/or dynamically created based on an instruction and/orattribute information provided by the PCE (and/or an edge device withintelligence similar to the PCE). As such, in some implementations, thesH-LSP may be an H-LSP for which creation, configuration, management,maintenance, or the like, requires fewer network resources, processingresources, memory resources, and/or less user configuration than atraditional H-LSP.

As shown in FIG. 1A, for example implementation 100, the PCE may receivethe indication to initiate the setup of the LSP and may determine (e.g.,based on a configuration of the PCE, based on performing trafficengineering for network 1, based on performing traffic engineering fornetwork 2, etc.) that a first sH-LSP is to be used on a first portion ofthe LSP (e.g., a sH-LSP from ND1 to ND5 that traverses network 1) andthat a second sH-LSP is to be used on a second portion of the LSP (e.g.,a sH-LSP from ND5 to ND12 that traverses network 2). In someimplementations, the PCE may determine whether sH-LSPs are to be used oneach portion of the LSP.

As further shown, after identifying that the first sH-LSP and the secondsH-LSP are to be used, the PCE may determine attribute informationassociated with the first sH-LSP and the second sH-LSP. The attributeinformation may include information that describes one or moreconfigurations of the sH-LSP such that the sH-LSP may be capable ofsupporting the traffic associated with the LSP. As shown, the PCE maydetermine first attribute information associated with the first sH-LSP(e.g., attribute information associated with the sH-LSP from ND1 to ND5)and second attribute information associated with the second sH-LSP(e.g., attribute information associated with the sH-LSP from ND5 toND12).

As further shown, the PCE may then provide, to ND1 (i.e., a first devicein the first sH-LSP) an indication associated with the first sH-LSP. Asshown, the indication may include an indication that the first sH-LSP isto be used for the first portion of the LSP (e.g., from ND1 to ND5,across network 1) and the first attribute information associated withthe first sH-LSP. As further shown, the PCE may also provide, to ND5(i.e., a first device in the second sH-LSP), an indication associatedwith the second sH-LSP. As shown, the indication may include anindication that the second sH-LSP is to be used for the second portionof the LSP (e.g., from ND5 to ND12, across network 2) and the secondattribute information associated with the second sH-LSP.

As shown in FIG. 1B, ND1 may receive the indication associated with thefirst sH-LSP, and may determine whether an existing sH-LSP is availablesuch that ND1 does not need to create the first sH-LSP. For example, ND1may determine that an existing sH-LSP (e.g., a sH-LSP already supportedby ND1) is available when an end of the existing sH-LSP matches an endof the first portion of the LSP (e.g., whether the ND1 already supportsa sH-LSP that ends at ND5), when configurations of the existing sH-LSPmatch the attribute information associated with the first sH-LSP, and/orwhen the existing sH-LSP has resources available to support the trafficassociated with the LSP.

As shown, assume that ND1 determines that there is no existing sH-LSPavailable and, therefore, that ND1 should create the first sH-LSP. Asshown, ND1 may create the first sH-LSP based on the first attributeinformation (e.g., a sH-LSP including ND1, ND4, and ND5). As furthershown, ND1 may provide, to the PCE, an identifier associated with thefirst sH-LSP. In some implementations, the identifier associated withthe first sH-LSP may be kept private such that only the PCE and ND1 arethe only devices to which the first sH-LSP identifier are known oraccessible. This may prevent overuse and/or congestion of the firstsH-LSP since other devices may not be capable of using the first sH-LSPfor other traffic flows.

As shown in FIG. 1C, ND5 may receive the indication associated with thesecond sH-LSP, and may determine (e.g., in a manner similar to thatdescribed above) whether an existing sH-LSP is available such that ND5does not need to create the second sH-LSP. As shown, assume that ND5determines that there is an existing sH-LSP available (e.g., a sH-LSPincluding ND5, ND8, ND7, ND10, and ND12) and, therefore, that ND1 shouldnot create the second sH-LSP. As shown, ND5 may provide, to the PCE, anidentifier associated with the second sH-LSP.

As shown in FIG. 1D, after the PCE receives the identifiers associatedwith the first sH-LSP and the second sH-LSP, the PCE may provide anindication associated with setting up the LSP (e.g., ND1-ND12 LSPSignal). As shown, the indication may include the identifiers associatedwith the first sH-LSP and the second sH-LSP. As further shown, the LSPmay be set up using the identifiers, and the LSP may be used to transfertraffic across network 1 and network 2.

In this way, one or more sH-LSPs may be identified and/or created, andan LSP may be set up using one or more identifiers corresponding to theone or more sH-LSPs. Notably, in example implementation 100, the firstsH-LSP and the second sH-LSP may be created before the LSP is set up(e.g., based on the identifiers). Example implementation 150 showsanother manner in which the LSP may be set up using sH-LSPs.

As shown in FIG. 1E, for example implementation 150, the PCE may receivethe indication to initiate the setup of the LSP and may determine thatthe first sH-LSP is to be used on the first portion of the LSP and thatthe second sH-LSP is to be used on the second portion of the LSP. Asfurther shown, after identifying that the first sH-LSP and the secondsH-LSP are to be used, the PCE may determine attribute informationassociated with the first sH-LSP and the second sH-LSP.

As further shown, the PCE may then provide, to ND1 (i.e., a first devicein the LSP), an indication associated with setting up the LSP (e.g., theND1-ND12 LSP Signal). As shown, the indication, associated with settingup the LSP, may include the first attribute information associated withthe first sH-LSP, and the second attribute information associated withthe second sH-LSP (e.g., rather than sH-LSP identifiers as describedwith regard to example implementation 100).

As shown in FIG. 1F, ND1 may receive the indication associated withsetting up the LSP, and may determine whether an existing sH-LSP isavailable such that ND1 does not need to create the first sH-LSP. Asshown, assume that ND1 determines that there is no existing sH-LSPavailable and, therefore, that ND1 should create the first sH-LSP. Asshown, ND1 may create the first sH-LSP based on the first attribute, andmay set up a portion of the LSP associated with the first sH-LSP (e.g.,such that a first portion of the LSP is set up).

As shown in FIG. 1G, ND1 may then provide the indication associated withsetting up the LSP to a next edge device associated with the LSP (e.g.,ND5 at the end of the first sH-LSP and the start of the second sH-LSP).As shown, ND5 may receive the indication associated with setting up theLSP, and may determine whether an existing sH-LSP is available such thatND5 does not need to create the second sH-LSP. As shown, assume that ND5determines that there is an existing sH-LSP available and, therefore,that ND5 should not create the second sH-LSP. As shown, ND5 may set up aportion of the LSP associated with the second sH-LSP (e.g., such thatthe first portion of the LSP and the second portion of the LSP are setup).

As shown in FIG. 1H, after ND5 sets up the second portion of the LSP(e.g., including the second sH-LSP), the set up of the LSP may becomplete, and the LSP (e.g., the LSP from ND1 to ND12) may be used totransfer traffic across network 1 and network 2.

In this way, an LSP may be set up concurrently with one or more sH-LSPsbeing identified and/or created based on attribute associated with theone or more sH-LSPs. Notably, in example implementation 150, the firstsH-LSP and the second sH-LSP may be created during setup of the LSP(e.g., based on the attribute information).

FIG. 2 is a diagram of an example environment 200 in which systemsand/or methods, described herein, may be implemented. As shown in FIG.2, environment 200 may include a PCE 205 and two or more networks 210-1through 210-N (N>1) (hereinafter referred to collectively as networks210, and individually as network 210). As shown, each network 210 mayinclude a group of edge devices 215 (e.g., edge device 215-1 at an edgeof network 210-1, edge device 215-1N at edges of network 210-1 andnetwork 210-N, and edge device 215-N at an edge of network 210-N), and agroup of network devices 220 (e.g., network device 220-1.1 throughnetwork device 220-1.A (A>1) included in network 210-1, and networkdevice 220-N.1 through network device 220-N.B (B>1) included in network210-N). Devices of environment 200 may interconnect via wiredconnections, wireless connections, or a combination of wired andwireless connections.

PCE 205 may include a device capable of identifying a portion of a LSPon which a sH-LSP is to be used to transfer traffic, determiningattribute information associated with the sH-LSP, and causing the LSP tobe set up such that the LSP includes the sH-LSP. For example, PCE 205may include a server, a group of servers, a gateway, a router, a switch,a server, a modem, a network interface card (NIC), a hub, a bridge, anoptical add-drop multiplexer (OADM), or the like. In someimplementations, PCE 205 may be capable of performing trafficengineering associated with one or more networks 210 by, for example,analyzing traffic data associated with the one or more networks 210.

Network 210 may include one or more wired and/or wireless labelswitching networks that support use of LSPs and sH-LSPs to transfertraffic. For example, network 210 may include a MPLS network, GMPLSnetwork, or the like. In some implementations, network 210 may include alocal area network (“LAN”), a wide area network (“WAN”), a metropolitanarea network (“MAN”), a telephone network (e.g., the Public SwitchedTelephone Network (“PSTN”)), an ad hoc network, an intranet, theInternet, a fiber optic-based network, a private network, a cloudcomputing network, and/or a combination of these or other types ofnetworks. In some implementations, network 210 may include a group ofedge devices 215 and a group of network devices 220.

Edge device 215 may include a device, positioned at an edge of one ormore networks 210, that is capable of creating, using, and/ormaintaining a sH-LSP. For example, edge device 215 may include a server,a group of servers, a gateway, a router, a switch, a server, a modem, aNIC, a hub, a bridge, an optical add-drop multiplexer OADM, or the like.In some implementations, edge device 215 may be positioned at edges ofone or more networks 210. In some implementations, edge device 215 mayinclude a LER associated with an MPLS network.

Network device 220 may include a device, positioned at an interior ofnetwork 210, that is capable of transferring traffic via a sH-LSP. Forexample, network device 220 may include a server, a group of servers, agateway, a router, a switch, a server, a modem, a NIC, a hub, a bridge,an optical add-drop multiplexer OADM, or the like. In someimplementations, network device 220 may include a LSR associated with anMPLS network.

The number and arrangement of devices and networks shown in FIG. 2 areprovided as an example. In practice, there may be additional devicesand/or networks, fewer devices and/or networks, different devices and/ornetworks, or differently arranged devices and/or networks than thoseshown in FIG. 2. Furthermore, two or more devices shown in FIG. 2 may beimplemented within a single device, or a single device shown in FIG. 2may be implemented as multiple, distributed devices. Additionally, oralternatively, a set of devices (e.g., one or more devices) ofenvironment 200 may perform one or more functions described as beingperformed by another set of devices of environment 200.

FIG. 3A is a diagram of example components of a device 300. Device 300may correspond to edge device 215 and/or network device 220. In someimplementations, edge device 215 and/or network device 220 may includeone or more devices 300 and/or one or more components of device 300. Asshown in FIG. 3A, device 300 may include one or more input components305-1 through 305-C (C≧1) (hereinafter referred to collectively as inputcomponents 305, and individually as input component 305), a switchingcomponent 310, one or more output components 315-1 through 315-D (D≧1)(hereinafter referred to collectively as output components 315, andindividually as output component 315), and a routing component 320.

Input component 305 may include points of attachment for physical linksand may be points of entry for traffic, such as packets. Input component305 may process received traffic, such as by performing data link layerencapsulation or decapsulation. In some implementations, input component305 may send packets to output component 315 via switching component310.

Switching component 310 may interconnect input components 305 withoutput components 315. Switching component 310 may be implemented usingone or more of multiple, different techniques. For example, switchingcomponent 310 may be implemented via busses, via crossbars, and/or withshared memories. The shared memories may act as temporary buffers tostore traffic from input components 305 before the traffic is eventuallyscheduled for delivery to output components 315. In someimplementations, switching component 310 may enable input components305, output components 315, and/or routing component 320 to communicate.

Output component 315 may include points of attachment for physical linksand may be points of exit for traffic, such as packets. Output component315 may store packets and may schedule packets for transmission onoutput physical links. Output component 315 may include schedulingalgorithms that support priorities and guarantees. Output component 315may support data link layer encapsulation or decapsulation, and/or avariety of higher-level protocols. In some implementations, outputcomponent 315 may send packets and/or receive packets.

Routing component 320 may include one or more processors,microprocessors, field-programmable gate arrays (FPGAs),application-specific integrated circuit (ASICs), or similar types ofprocessing components. In some implementations, routing component 320may communicate with other devices, networks, and/or systems connectedto device 300 to exchange information regarding network topology.Routing component 320 may create routing tables based on the networktopology information, create forwarding tables based on the routingtables, and forward the forwarding tables to input components 305 and/oroutput components 315. Input components 305 and/or output components 315may use the forwarding tables to perform route lookups for incomingpackets.

The number and arrangement of components shown in FIG. 3A are providedas an example. In practice, device 300 may include additionalcomponents, fewer components, different components, or differentlyarranged components than those shown in FIG. 3A. Additionally, oralternatively, a set of components (e.g., one or more components) ofdevice 300 may perform one or more functions described as beingperformed by another set of components of device 300.

FIG. 3B is a diagram of example components of a device 325. Device 325may correspond to PCE 205. In some implementations, PCE 205 may includeone or more devices 325 and/or one or more components of device 325. Asshown in FIG. 3B, device 325 may include a bus 330, a processor 335, amemory 340, a storage component 345, an input component 350, an outputcomponent 355, and a communication interface 360.

Bus 330 may include a component that permits communication among thecomponents of device 325. Processor 335 is implemented in hardware,firmware, or a combination of hardware and software. Processor 335 mayinclude a processor (e.g., a central processing unit (CPU), a graphicsprocessing unit (GPU), an accelerated processing unit (APU), etc.), amicroprocessor, and/or any processing component (e.g., an FPGA, an ASIC,etc.) that interprets and/or executes instructions. In someimplementations, processor 335 may include one or more processors thatare programmed to perform a function. Memory 340 may include a randomaccess memory (RAM), a read only memory (ROM), and/or another type ofdynamic or static storage device (e.g., a flash memory, a magneticmemory, an optical memory, etc.) that stores information and/orinstructions for use by processor 335.

Storage component 345 may store information and/or software related tothe operation and use of device 325. For example, storage component 345may include a hard disk (e.g., a magnetic disk, an optical disk, amagneto-optic disk, a solid state disk, etc.), a compact disc (CD), adigital versatile disc (DVD), a floppy disk, a cartridge, a magnetictape, and/or another type of computer-readable medium, along with acorresponding drive.

Input component 350 may include a component that permits device 325 toreceive information, such as via user input (e.g., a touch screendisplay, a keyboard, a keypad, a mouse, a button, a switch, amicrophone, etc.). Additionally, or alternatively, input component 350may include a sensor for sensing information (e.g., a global positioningsystem (GPS) component, an accelerometer, a gyroscope, an actuator,etc.). Output component 355 may include a component that provides outputinformation from device 325 (e.g., a display, a speaker, one or morelight-emitting diodes (LEDs), etc.).

Communication interface 360 may include a transceiver-like component(e.g., a transceiver, a separate receiver and transmitter, etc.) thatenables device 325 to communicate with other devices, such as via awired connection, a wireless connection, or a combination of wired andwireless connections. Communication interface 360 may permit device 325to receive information from another device and/or provide information toanother device. For example, communication interface 360 may include anEthernet interface, an optical interface, a coaxial interface, aninfrared interface, a radio frequency (RF) interface, a universal serialbus (USB) interface, a Wi-Fi interface, a cellular network interface, orthe like.

Device 325 may perform one or more processes described herein. Device325 may perform these processes in response to processor 335 executingsoftware instructions stored by a non-transitory computer-readablemedium, such as memory 340 and/or storage component 345. Acomputer-readable medium is defined herein as a non-transitory memorydevice. A memory device includes memory space within a single physicalstorage device or memory space spread across multiple physical storagedevices.

Software instructions may be read into memory 340 and/or storagecomponent 345 from another computer-readable medium or from anotherdevice via communication interface 360. When executed, softwareinstructions stored in memory 340 and/or storage component 345 may causeprocessor 335 to perform one or more processes described herein.Additionally, or alternatively, hardwired circuitry may be used in placeof or in combination with software instructions to perform one or moreprocesses described herein. Thus, implementations described herein arenot limited to any specific combination of hardware circuitry andsoftware.

The number and arrangement of components shown in FIG. 3B are providedas examples. In practice, device 325 may include additional components,fewer components, different components, or differently arrangedcomponents than those shown in FIG. 3B. Additionally, or alternatively,a set of components (e.g., one or more components) of device 325 mayperform one or more functions described as being performed by anotherset of components of device 325.

FIG. 4 is a flow chart of an example process 400 for providing anindication, associated with setting up a LSP, that includes anidentifier associated with a sH-LSP. In some implementations, one ormore process blocks of FIG. 4 may be performed by PCE 205 and/or edgedevice 215. In some implementations, one or more process blocks of FIG.4 may be performed by another device or a group of devices separate fromor including PCE 205 and/or edge device 215, such as one or more networkdevice 220.

As shown in FIG. 4, process 400 may include identifying a portion of aLSP on which a simple hierarchical LSP is to be used for traffic to beprovided via a network (block 410). For example, PCE 205 may identify aportion of a LSP on which a sH-LSP is to be used for traffic to beprovided via network 210. In some implementations, PCE 205 may identifythe portion of the LSP when PCE 205 receives information indicating thatthe traffic is to be provided via network 210.

The sH-LSP may include an H-LSP that is automatically (e.g., withoutuser intervention) and/or dynamically created or identified based on aninstruction and/or attribute information provided by PCE 205 (and/oredge device 215 with intelligence similar to PCE 205). As such, in someimplementations, the sH-LSP may be an H-LSP for which creation,configuration, management, maintenance, or the like, requires fewernetwork resources, processing resources, memory resources, and/or lessuser configuration than a traditional H-LSP. For example, since thesH-LSP may be automatically and/or dynamically created based on theinstruction and the attribute information, an edge device associatedwith the sH-LSP need not have intelligence to determine whether tocreate the sH-LSP, may not need to store state information associatedwith the sH-LSP, and/or may not need to advertise a link associated withthe sH-LSP.

The LSP may include a network path through one or more networks 210(e.g., one or more MPLS networks), including one or more edge devices215 and one or more network devices 220, via which the traffic is totravel based on label switching. In some implementations, PCE 205 may beconfigured to cause traffic to traverse the one or more networks 210(e.g., via edge devices 215 and network devices 220) using an LSP (e.g.,an overlay LSP including one or more sH-LSPs). In some implementations,the LSP may traverse multiple networks 210. In some implementations, PCE205 may identify (e.g., based on a configuration of PCE 205, based oninformation associated with the one or more edge devices 215 and/or oneor more network devices 220, based on information associated withnetwork 210, etc.) one or more portions of the LSP on which sH-LSPs areto be used, as described below.

In some implementations, PCE 205 may identify the portion of the LSP onwhich the sH-LSP is to be used based on analyzing information associatedwith network 210. For example, PCE 205 may be configured to perform(e.g., in order to improve performance of network 210) trafficengineering for network 210 by, for example, analyzing, predictingand/or regulating behavior of traffic travelling via network 210. Here,as a result of performing traffic engineering, PCE 205 may identify theportion of the LSP on which the sH-LSP is to be used. In someimplementations, the portion of the LSP may correspond to a particularnetwork 210 (e.g., such that each portion of the LSP is associated witha different network 210).

Additionally, or alternatively, PCE 205 may identify the portion of theLSP based on information associated with network 210. For example, PCE205 may be store or have access to network policy information indicatingthat PCE 205 is to minimize a total number LSPs in network 210. In thisexample, PCE 205 may identify the portion of the LSP based on thenetwork policy information (e.g., such that the portion of the LSP thatlies within network 210 uses a sH-LSP).

Additionally, or alternatively, PCE 205 may identify the portion of theLSP based on information associated with edge devices 215 and/or networkdevices 220 of network 210. For example, PCE 205 may store or haveaccess to device policy information indicating that PCE 205 is tominimize an amount of memory used by one or more edge devices 215 and/orone or more network devices 220 to store state information associatedwith transferring traffic. In this example, PCE 205 may identify theportion of the LSP based on the device policy information (e.g., suchthat the portion of the LSP that includes the one or more edge devices215 and/or the one or more network devices 220 uses a sH-LSP).

Additionally, or alternatively, PCE 205 may identify the portion of theLSP based on receiving user input indicating that the portion of the LSPis to use the sH-LSP.

In some implementations, PCE 205 may identify one or more portions ofthe LSP on which sH-LSPs are to be used. For example, assume that a LSPincludes a first portion associated with a first network 210, a secondportion associated with a second network 210, and a third portionassociated with a third network 210. Here, in this example, PCE 205 mayidentify (e.g., based on performing traffic engineering) that a firstsH-LSP is to be used on the first portion of the LSP, that a sH-LSP isnot to be used on the second portion of the LSP, and that a secondsH-LSP is to be used on the third portion of the LSP.

As such, in some implementations, PCE 205 may identify one or moreportions of the LSP on which sH-LSPs are not to be used. In such a case,PCE 205 may determine a manner in which the traffic is to traverse theone or more portions of the LSP on which sH-LSPs are not to be used,such as using a strict network hop, a loose network hop, or the like.

As further shown in FIG. 4, process 400 may include determiningattribute information associated with the simple hierarchical LSP (block420). For example, PCE 205 may determine attribute informationassociated with the sH-LSP. In some implementations, PCE 205 maydetermine the attribute information when (e.g., before, after,concurrently with, etc.) PCE 205 identifies the portion of the LSP onwhich the sH-LSP is to be used for the traffic.

The attribute information, associated with the sH-LSP, may includeinformation that describes one or more configurations of the sH-LSP suchthat the sH-LSP may be capable of supporting the traffic. For example,the attribute information may include information associated with anattribute flag configuration, information associated with an automaticbandwidth configuration, information associated with a sH-LSP bandwidthconfiguration, information associated with a re-optimizationconfiguration, information associated with a priority configuration,information associated with a failure protection configuration,information associated with a route recording configuration, or thelike.

In some implementations, PCE 205 may determine the attribute informationbased on identifying the portion of the LSP on which the sH-LSP is to beused. For example, as described above, PCE 205 may perform trafficengineering to identify the portion of the LSP on which the sH-LSP is tobe used. Here, the result of the traffic engineering may also identifyone or more configurations of the sH-LSP that are needed to supporttransfer of the traffic via the sH-LSP.

In some implementations, PCE 205 may determine attribute informationthat includes one or more configurations of the sH-LSP. Additionally, oralternatively, PCE 205 may determine attribute information that includesa sH-LSP profile. For example, PCE 205 may store or have access to a setof sH-LSP profiles, where each sH-LSP profile is associated with adifferent set of sH-LSP configurations. Here, PCE 205 may determine theattribute information in the manner described above, and may identify aparticular sH-LSP profile, of the set of sH-LSP profiles, that includesattribute information that matches (e.g., meets, exceeds, matches withina configuration threshold, etc.) the attribute information determined byPCE 205. In some implementations, information associated with the set ofsH-LSP profiles may be stored or accessible by PCE 205.

In some implementations, PCE 205 may determine attribute information formultiple sH-LSPs. For example, if PCE 205 determines that a first sH-LSPis to be used on a first portion of the LSP, and that a second sH-LSP isto be used on a second (e.g., different) portion of the LSP, then PCE205 may determine first attribute information for the first sH-LSP andsecond attribute information for the second sH-LSP.

As further shown in FIG. 4, process 400 may include providing anindication, associated with the sH-LSP, that includes the attributeinformation (block 430). For example, PCE 205 may provide an indication,associated with the sH-LSP, that includes the attribute information. Insome implementations, PCE 205 may provide the indication including theattribute information after PCE 205 determines the attribute informationassociated with the sH-LSP.

The indication may include an indication to identify an available sH-LSPbased on the attribute information, or create a sH-LSP based on theattribute information (e.g., when no available sH-LSP is identified). Insome implementations, PCE 205 may provide the indication in an objectassociated with a path computation protocol such as an explicit routeobject (ERO) associated with a PCE Communication Protocol (PCEP), oranother type of protocol associated with providing a path computationfunction. In such a case, PCE 205 may provide the indication in anattribute flag type-length-value (TLV) carried in a sub-object of theERO, such as an ERO_HOP_ATTRIBUTES sub-object.

In some implementations, PCE 205 may provide the indication to edgedevice 215 associated with the sH-LSP. For example, assume that PCE 205determines that a first sH-LSP is to be used on a first portion of theLSP, determines first attribute information associated with the firstsH-LSP, determines that a second sH-LSP is to be used on a secondportion of the LSP, and determines second attribute informationassociated with the second sH-LSP. Here, PCE 205 may provide, to aningress edge device 215 of the first sH-LSP, a first object thatincludes the first attribute information. PCE 205 may similarly provide,to an ingress edge device 215 of the second sH-LSP, a second object thatincludes the second attribute information.

In some implementations, the indication may include information thatidentifies the portion of the LSP on which the sH-LSP is to be used. Forexample, the indication may include information (e.g., a networkaddress, a device name, a device identifier, etc.) that identifies edgedevice 215 at which the sH-LSP is to start (e.g., an ingress edge device215), edge device 215 at which the sH-LSP is to end (e.g., an egressedge device 215), network 210 associated with the sH-LSP, or the like.

In some implementations, PCE 205 may also provide the attributeinformation in the object. For example, PCE 205 may provide theattribute information by including information that identifies thesH-LSP profile (e.g., a profile name, a profile identifier, etc.) in ahop-attribute TLV of the ERO (e.g., a SYMBOLIC-PROFILE-NAMEhop-attribute TLV). As another example, PCE 205 may provide theattribute information by including information that identifies one ormore configurations of the sH-LSP in the ERO (e.g., such that each ofthe one or more configurations is signaled separately within the ERO).

As further shown in FIG. 4, process 400 may include receiving theindication, associated with the sH-LSP, that includes the attributeinformation (block 440). For example, edge device 215 may receive theindication, associated with the sH-LSP, that includes the attributeinformation. In some implementations, edge device 215 may receive theindication when PCE 205 provides the indication.

In some implementations, the indication may include the objectassociated with the path computation protocol. For example, theindication may include the ERO associated with PCEP, where the ERO mayinclude the attribute information associated with the sH-LSP.

As further shown in FIG. 4, process 400 may include identifying anavailable sH-LSP based on the attribute information or creating a sH-LSPbased on the attribute information (block 450). For example, edge device215 may identify an available sH-LSP based on the attribute informationor create a sH-LSP based on the attribute information. In someimplementations, edge device 215 may identify an available sH-LSP orcreate a sH-LSP when edge device 215 receives the indication, associatedwith the sH-LSP, that includes that attribute information.

In some implementations, edge device 215 may identify an availablesH-LSP based when an existing sH-LSP (e.g., already supported by edgedevice 215) is available to support traffic such that a new sH-LSP neednot be created. In other words, edge device 215 may determine whether asH-LSP exists such that edge device 215 does not need to create anadditional sH-LSP.

In some implementations, edge device 215 may identify an availablesH-LSP based on information associated with an existing sH-LSP. Forexample, edge device 215 may store or have access to informationassociated with one or more existing sH-LSPs supported by edge device215. Here, edge device 215 may determine that an existing sH-LSP isavailable based on, for example, determining whether an end of theexisting sH-LSP matches an end of the sH-LSP associated with theindication (e.g., a same edge device 215, a same network address, etc.).Alternatively, edge device 215 may determine that no existing sH-LSP isavailable when the end of the sH-LSP, associated with the indication, isnot shared with any existing sH-LSP. Similarly, edge device 215 maydetermine that no existing sH-LSP is available when no sH-LSPs are beingsupported by edge device 215.

Additionally, or alternatively, edge device 215 may determine whether anexisting sH-LSP is available based on one or more configurations of theexisting sH-LSP. For example, edge device 215 may determine whetherconfigurations of the existing sH-LSP match (e.g., meet, exceed, matchwithin a threshold, etc.) configurations included in the attributeinformation provided by PCE 205. As an example, edge device 215 maydetermine whether a sH-LSP bandwidth configuration of the existingsH-LSP matches a sH-LSP bandwidth configuration included in theattribute information, and may determine whether the sH-LSP isavailable, accordingly. As another example, edge device 215 maydetermine whether a profile associated with the existing sH-LSP matchesa profile identified in the attribute information.

Additionally, or alternatively, edge device 215 may determine whether asH-LSP is available based on usage information associated with theexisting sH-LSP. For example, edge device 215 may determine a number ofother LSPs that are using the existing sH-LSP and may determine whetherthe existing sH-LSP is available based on whether the number of otherLSPs that are using the existing sH-LSP satisfies a usage threshold. Asanother example, edge device 215 may determine an amount of unusedbandwidth associated with the existing sH-LSP, and may determine whetherexisting sH-LSP is available based on whether the amount of unusedbandwidth satisfies a threshold and/or is sufficient to support thetraffic.

In some implementations, when the end of the existing sH-LSP matches theend of the sH-LSP associated with the indication, when theconfigurations of the existing sH-LSP match the attribute information,and when the usage information of the existing sH-LSP indicates that theexisting sH-LSP can support the traffic, then edge device 215 mayidentify the existing sH-LSP as an available sH-LSP (e.g., such thatedge device 215 does not need to create a sH-LSP).

Alternatively, when the end of the existing sH-LSP does not match theend of the sH-LSP associated with the indication, when theconfigurations of the existing sH-LSP do not match the attributeinformation, when the usage information of the existing sH-LSP indicatesthat the existing sH-LSP cannot support the traffic, or when edge device215 does not currently support any sH-LSPs, then edge device 215 may notidentify the existing sH-LSP as an available sH-LSP. In someimplementations, edge device 215 may determine that no existing sH-LSP,supported by edge device 215, is available.

In some implementations, when edge device 215 does not identify anavailable sH-LSP, edge device 215 may create the sH-LSP based on theattribute information. For example, edge device 215 may create thesH-LSP based on the one or more configurations included in the attributeinformation. As another example, edge device 215 may create the sH-LSPbased on a profile identified in the attribute information (e.g., whenedge device 215 stores or has access to configurations corresponding tothe profile).

In some implementations, the sH-LSP, created by edge device 215, may beused within another LSP (e.g., a LSP created at a later time). Forexample, the created sH-LSP may be seen as an existing sH-LSP during setup of another LSP at a later time, and edge device 215 may determinewhether the created sH-LSP is available for use on a portion of theother LSP in the manner described above.

As further shown in FIG. 4, process 400 may include providing anidentifier associated with the available sH-LSP or the created sH-LSP(block 460). For example, edge device 215 may provide an identifierassociated with the available sH-LSP or the created sH-LSP. In someimplementations, edge device 215 may provide the identifier, associatedwith the available sH-LSP, when edge device 215 identifies the availablesH-LSP. Additionally, or alternatively, edge device 215 may provide theidentifier, associated with the created sH-LSP, when edge device 215creates the sH-LSP.

In some implementations, the identifier may include information thatidentifies the available sH-LSP or the created sH-LSP, such as a TE-linkidentifier. In some implementations, edge device 215 may provide theidentifier to PCE 205. For example, edge device 215 may be configured toautomatically provide the identifier, associated with the availablesH-LSP, after edge device 215 identifies the available sH-LSP. Asanother example, edge device 215 may be configured to automaticallyprovide the identifier, associated with the created sH-LSP, after edgedevice 215 creation of the sH-LSP is complete. In some implementations,the identifier associated with the sH-LSP may be kept private such thatonly PCE 205 and/or network device 220 that created the sH-LSP store orhave access to the identifier. Here, PCE 205 and/or network device 220may monitor and/or manage usage of the sH-LSP in order to preventoveruse and/or traffic congestion of the sH-LSP.

In some implementations, multiple edge devices 215 may providecorresponding multiple identifiers. For example, a first edge device215, associated with a first sH-LSP corresponding to a first portion ofthe LSP, may provide a first identifier associated with a sH-LSP createdby the first edge device 215 (e.g., based on a first indication providedby PCE 205). Here, a second edge device 215, associated with a secondsH-LSP corresponding to a second portion of the LSP, may provide asecond identifier associated with a sH-LSP identified as available(e.g., based on a second indication provided by PCE 205). In someimplementations, PCE 205 may set up the LSP based on the multipleidentifiers, as described below.

As further shown in FIG. 4, process 400 may include receiving theidentifier associated with the available sH-LSP or the created sH-LSP(block 470). For example, PCE 205 may receive the identifier associatedwith the available sH-LSP or the created sH-LSP. In someimplementations, PCE 205 may receive the identifier when edge device 215provides the identifier. In some implementations, PCE 205 may receivemultiple identifiers corresponding to multiple sH-LSPs to be included inthe LSP.

As further shown in FIG. 4, process 400 may include providing anindication, associated with setting up the LSP, that includes theidentifier (block 480). For example, PCE 205 may provide an indication,associated with setting up the LSP, that includes the identifier. Insome implementations, PCE 205 may provide the indication after PCE 205receives the identifier. Additionally, or alternatively, PCE 205 mayprovide the indication when PCE receives information indicating that PCEis to provide the indication associated with setting up the LSP.

In some implementations, the indication may include an object associatedwith setting up the LSP for transfer of the traffic, such as an EROassociated with a Resource Reservation Protocol (RSVP), or anotherprotocol associated with setting up an LSP. For example, the indicationmay include an RSVP ERO, associated with setting up an LSP, thatincludes a TE-link identifier associated with the sH-LSP.

In some implementations, PCE 205 may provide the indication in order tocause the LSP to be set up based on the identifier. For example, assumethat PCE 205 receives a first identifier corresponding to a first sH-LSPto be included in the LSP, and a second identifier corresponding to asecond sH-LSP to be included in the LSP. Here, PCE 205 may provide theindication to a first edge device 215 associated with the first sH-LSP.The first edge device 215 may, using the first identifier, set up afirst portion of the LSP such that the LSP includes the first sH-LSP.The first edge device 215 may provide (e.g., forward) the indication toa second edge device 215 associated with the second sH-LSP. The secondedge device 215 may, using the second identifier, set up a secondportion of the LSP such that the LSP includes the second sH-LSP.

In this way, PCE 205 may cause a LSP to be set up based on one or moreidentifiers associated with one or more sH-LSPs to be included in theLSP. Notably, as described with respect to process 400, PCE 205 maycause the one or more sH-LSPs to be identified as available and/orcreated before PCE 205 initiates set up of the LSP. However, in someimplementations, PCE 205 may cause the one or more sH-LSPs to beidentified as available and/or created concurrently with causing the LSPto be set up, as described below with respect to process 500.

Although FIG. 4 shows example blocks of process 400, in someimplementations, process 400 may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 4. Additionally, or alternatively, two or more of theblocks of process 400 may be performed in parallel.

FIG. 5 is a flow chart of an example process 500 for providing anindication, associated with setting up a LSP, that includes attributeinformation associated with a sH-LSP. In some implementations, one ormore process blocks of FIG. 5 may be performed by PCE 205 and/or edgedevice 215. In some implementations, one or more process blocks of FIG.5 may be performed by another device or a group of devices separate fromor including PCE 205 and/or edge device 215, such as one or more networkdevice 220.

As shown in FIG. 5, process 500 may include identifying a portion of aLSP on which a simple hierarchical LSP is to be used for traffic to beprovided via a network (block 510). For example, PCE 205 may identify aportion of a LSP on which a sH-LSP is to be used for traffic to beprovided via network 210, in a manner similar to that described abovewith regard to FIG. 4

As further shown in FIG. 5, process 500 may include determiningattribute information associated with the simple hierarchical LSP (block520). For example, PCE 205 may determine attribute informationassociated with the sH-LSP, in a manner similar to that described abovewith regard to FIG. 4.

As further shown in FIG. 5, process 500 may include providing anindication, associated with setting up the LSP, that includes theattribute information (block 530). For example, PCE 205 may provide anindication, associated with setting up the LSP, that includes theattribute information. In some implementations, PCE 205 may provide theindication after PCE 205 determines the attribute information.Additionally, or alternatively, PCE 205 may provide the indication whenPCE receives information indicating that PCE is to provide theindication associated with setting up the LSP.

In some implementations, the indication may include an object associatedwith setting up the LSP for transfer of the traffic based on identifyingan available sH-LSP using the attribute information or creating a sH-LSPusing the attribute information. For example, the indication may includean RSVP ERO, associated with setting up the LSP, that includes theattribute information associated with the sH-LSP. In such a case, PCE205 may provide the indication in an attribute TLV carried in asub-object of the ERO, such as an ERO_HOP_ATTRIBUTES sub-object. Theindication, associated with setting up the LSP, may include theattribute information associated with the sH-LSP (e.g., rather than anidentifier associated with the sH-LSP, as described with regard toexample process 400, since PCE 205 may not have knowledge of theidentifier and/or the sH-LSP may not yet exist).

In some implementations, PCE 205 may provide the indication to a firstedge device 215 associated with the LSP (e.g., a head-end node of theLSP). In some implementations, PCE 205 may provide the indication inorder to cause the LSP to be set up based on identifying availablesH-LSPs or creating sH-LSPs using the attribute information, asdescribed in further detail below.

As further shown in FIG. 5, process 500 may include receiving theindication, associated with setting up the LSP, that includes theattribute information (block 540). For example, edge device 215 (e.g.,the head-end node of the LSP) may receive the indication, associatedwith setting up the LSP, that includes the attribute information. Insome implementations, edge device 215 may receive the indication whenPCE 205 provides the indication.

As further shown in FIG. 5, process 500 may include identifying anavailable sH-LSP based on the attribute information or creating a sH-LSPbased on the attribute information (block 550). For example, edge device215 may identify an available sH-LSP based on the attribute informationor create a sH-LSP based on the attribute information, in a mannersimilar to that described above with regard to FIG. 4.

In some implementations, edge device 215 may determine whether a sH-LSPis available after determining whether a sH-LSP is to be used on aportion of the LSP associated with edge device 215. For example, assumePCE 205 provides an indication that a sH-LSP is to be used on a secondportion of the LSP (e.g., a second portion starting at a second edgedevice 215 and at an end of a first portion of the LSP), but not on thefirst portion of the LSP (e.g., starting at a first edge device 215).Here, when the first edge device 215 receives the object, the first edgedevice 215 may determine that a sH-LSP is not to be used on the firstportion of the LSP and (e.g., after setting up the portion of the LSP insome other manner, such as using a strict hop, a loose hop, etc.) mayprovide the object to the second edge device 215. The second edge device215 may then determine, based on the indication, that a sH-LSP is to beused on the second portion of the LSP, and may proceed with determiningwhether a sH-LSP is available for use on the portion of the LSP.

In some implementations, based on identifying the available sH-LSP orcreating the sH-LSP, edge device 215 may set up the LSP such that theLSP includes the available sH-LSP or the created sH-LSP. In other words,the LSP may be set up concurrently with the identification of theavailable sH-LSP or the creation of the sH-LSP (e.g., rather thanproviding an identifier associated with the sH-LSP such that the sH-LSPmay be set up at a later time, as described in connection with process400).

For example, assume that PCE 205 determines attribute information for afirst sH-LSP to be included in the LSP, and attribute information for asecond sH-LSP to be included in the LSP. Here, PCE 205 may provide theindication (e.g., including the first and second attribute information)to a first edge device 215 associated with the first sH-LSP. The firstedge device 215 may, using the first attribute information, identify afirst available sH-LSP or create a first sH-LSP, and may then set up afirst portion of the LSP such that the LSP includes the first availablesH-LSP or the first created sH-LSP. The first edge device 215 may thenprovide (e.g., forward) the indication to a second edge device 215associated with the second sH-LSP, as described below. The second edgedevice 215 may, using the second attribute information, identify asecond available sH-LSP or create a second sH-LSP, and may then set up asecond portion of the LSP such that the LSP includes the secondavailable sH-LSP or the second created sH-LSP. This process may berepeated until the entire LSP is set up (e.g., including multiplesH-LSPs).

As further shown in FIG. 5, process 500 may include providing theindication, associated with setting up the LSP (block 560). For example,edge device 215 may provide the indication associated with setting upthe LSP. In some implementations, edge device 215 may provide theindication after edge device 215 identifies the available sH-LSP orcreates the sH-LSP. Additionally, or alternatively, edge device 215 mayprovide the indication when edge device 215 sets up a portion of the LSPassociated with the available sH-LSP or the created sH-LSP.

In some implementations, edge device 215 may forward the indication,provided by PCE 205, to another edge device 215 such that the other edgedevice 215 may identify an available sH-LSP or create an LSP, and set upanother portion of the LSP, as described in the above example.

Notably, as described with respect to process 500, PCE 205 may cause theone or more sH-LSPs to be identified as available and/or created duringsetup of the LSP (e.g., rather than before setup of the LSP, asdescribed with regard to process 400).

Although FIG. 5 shows example blocks of process 500, in someimplementations, process 500 may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 5. Additionally, or alternatively, two or more of theblocks of process 500 may be performed in parallel.

Implementations described herein may provide for a simple H-LSP (sH-LSP)for which management is simplified such that an amount of resourcesand/or an amount of user configuration is reduced (e.g., as compared toa traditional H-LSP). In some implementations, a sH-LSP differs from atraditional H-LSP in that a centralized entity, such as a PCE, may causethe sH-LSP to be created (while is not possible for a centralized entityto cause a traditional H-LSP to be created). For example, the PCE mayindicate that the sH-LSP is to be used on a particular portion of a LSPassociated with a network and, thus, may instruct another device tocreate the sH-LSP or identify of an existing sH-LSP for use in the LSP.The sH-LSP also differs from the traditional H-LSP in that the sH-LSPmay be kept private (i.e., not advertised) such that only the PCE and ahead end node, associated with the sH-LSP, know of the existence of thesH-LSP (while existence of the traditional H-LSP may be advertised toother devices).

In some implementations, the PCE may cause the LSP to be set up afterthe PCE receives an identifier associated with the sH-LSP. In someimplementations, after the sH-LSP is created, the sH-LSP identifier(e.g., a TE link identifier) may be kept private (i.e., may notadvertised) such that only the PCE and/or a head end node of the sH-LSPstore or have access to the sH-LSP identifier. This may prevent overuseand/or congestion of the sH-LSP since the PCE may monitor and/or manageuse of the sH-LSP for various traffic flows. In some implementations,the PCE may cause the LSP to be set up based on providing attributeinformation associated with the sH-LSP (e.g., such that the sH-LSP iscreated or identified during setup of the LSP).

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the implementations to theprecise form disclosed. Modifications and variations are possible inlight of the above disclosure or may be acquired from practice of theimplementations.

As used herein, the term component is intended to be broadly construedas hardware, firmware, and/or a combination of hardware and software.

Some implementations are described herein in connection with thresholds.As used herein, satisfying a threshold may refer to a value beinggreater than the threshold, more than the threshold, higher than thethreshold, greater than or equal to the threshold, less than thethreshold, fewer than the threshold, lower than the threshold, less thanor equal to the threshold, equal to the threshold, etc.

It will be apparent that systems and/or methods, described herein, maybe implemented in different forms of hardware, firmware, or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the implementations. Thus, the operation and behaviorof the systems and/or methods were described herein without reference tospecific software code—it being understood that software and hardwarecan be designed to implement the systems and/or methods based on thedescription herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of possible implementations. In fact,many of these features may be combined in ways not specifically recitedin the claims and/or disclosed in the specification. Although eachdependent claim listed below may directly depend on only one claim, thedisclosure of possible implementations includes each dependent claim incombination with every other claim in the claim set.

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the terms “group” and “set” are intended to include oneor more items (e.g., related items, unrelated items, a combination ofrelated items and unrelated items, etc.), and may be usedinterchangeably with “one or more.” Where only one item is intended, theterm “one” or similar language is used. Also, as used herein, the terms“has,” “have,” “having,” or the like are intended to be open-endedterms. Further, the phrase “based on” is intended to mean “based, atleast in part, on” unless explicitly stated otherwise.

What is claimed is:
 1. A method, comprising: identifying, by a device, aportion of a label-switched path (LSP) on which a simple hierarchicalLSP (sH-LSP) is to be used for transferring traffic via a network;determining, by the device, attribute information associated with thesH-LSP, the attribute information including information associated withone or more characteristics of the sH-LSP; providing, by the device, anindication associated with identifying an available sH-LSP or creating asH-LSP, the indication including the attribute information associatedwith the sH-LSP, and the indication being provided to cause the sH-LSPto be created on the portion of the LSP or an available sH-LSP,associated with the portion of the LSP, to be identified; receiving, bythe device and based on providing the indication, an identifierassociated with the sH-LSP; and causing, by the device, the LSP to beset up based on the identifier associated with the sH-LSP.
 2. The methodof claim 1, where identifying the portion of the LSP comprises:performing traffic engineering in connection with the network; andidentifying the portion of the LSP based on a result of performing thetraffic engineering in connection with the network.
 3. The method ofclaim 1, where determining the attribute information comprises:determining attribute information that identifies one or moreconfigurations of the sH-LSP; and identifying a profile, of a pluralityof profiles, that substantially matches the one or more configurationsof the sH-LSP.
 4. The method of claim 1, where the indication associatedwith identifying an available sH-LSP or creating a sH-LSP includes anexplicit route object (ERO).
 5. The method of claim 4, where the ERO isassociated with a Path Computation Element Communication Protocol. 6.The method of claim 1, where the portion of the LSP is a first portionof the LSP, the sH-LSP is a first sH-LSP, the network is a firstnetwork, the attribute information is first attribute information, theindication includes a first indication, and the identifier includes afirst identifier: where the method further comprises: identifying asecond portion of the LSP on which a second sH-LSP is to be used fortransferring the traffic via a second network, the second portion of theLSP being different from the first portion of the LSP, the second sH-LSPbeing different from the first sH-LSP, and the second network beingdifferent from the first network; and determining second attributeinformation associated with the second sH-LSP; providing a secondindication associated with identifying an available sH-LSP or creating asH-LSP, the second indication including the second attribute informationassociated with the second sH-LSP, the second indication being providedto cause the second sH-LSP to be created on the second portion of theLSP or an available sH-LSP, associated with the second portion of theLSP, to be identified; receiving, based on providing the secondindication, a second identifier associated with the second sH-LSP; andcausing the LSP to be set up based on the second identifier associatedwith the second sH-LSP.
 7. The method of claim 1, where the networkincludes a Multi-Protocol Label Switching (MPLS) network or aGeneralized MPLS network.
 8. A device, comprising: one or moreprocessors to: identify a first portion of a label-switched path (LSP)for which a first simple hierarchical LSP (sH-LSP) is to be used totransfer traffic across a network; determine first attribute informationassociated with the first sH-LSP, the first attribute informationidentifying one or more characteristics of the first sH-LSP; provideinformation associated with setting up the LSP, the informationincluding information indicating that the first sH-LSP is to be used onthe first portion of the LSP and the first attribute informationassociated with the first sH-LSP, and the information being provided tocause the first sH-LSP to be automatically created on the first portionof the LSP or to cause an available sH-LSP, existing on the firstportion of the LSP, to be identified; identify a second, differentportion of the LSP for which a second, different sH-LSP is to be used totransfer traffic across a second, different network; and determinesecond attribute information associated with the second, differentsH-LSP, the information associated with setting up the LSP furtherincluding: an indication that the second, different sH-LSP is to be usedon the second, different portion of the LSP and the second attributeinformation associated with the second, different sH-LSP.
 9. The deviceof claim 8, where the one or more processors, when identifying the firstportion of the LSP, are to: perform traffic engineering in connectionwith the network; and identify the first portion of the LSP based on aresult of performing the traffic engineering in connection with thenetwork.
 10. The device of claim 8, where the one or more processors,when identifying the first portion of the LSP, are to: determine networkpolicy information associated with the network; and identify the firstportion of the LSP based on the network policy information associatedwith the network.
 11. The device of claim 8, where the one or moreprocessors, when determining the first attribute information associatedwith the first sH-LSP, are to: determine attribute information thatidentifies one or more configurations of the first sH-LSP; and identifya profile, of a plurality of profiles, that matches the one or moreconfigurations of the first sH-LSP.
 12. The device of claim 8, where theinformation associated with setting up the LSP includes an explicitroute object (ERO) associated with a Resource Reservation Protocol. 13.The device of claim 8, where the information associated with setting upthe LSP is provided to cause the second, different sH-LSP to be createdon the second, different portion of the LSP, or to cause an availablesH-LSP, existing on the second, different portion of the LSP, to beidentified.
 14. The device of claim 8, where the network includes aMulti-Protocol Label Switching (MPLS) network or a Generalized MPLSnetwork.
 15. A method comprising: receiving, by a device, an indicationassociated with a simple hierarchical label switched path (sH-LSP), thesH-LSP being associated with a portion of a LSP, and the indicationincluding attribute information associated with the sH-LSP; determining,by the device, whether an existing sH-LSP, associated with the portionof the LSP, is available to be used on the portion of the LSP;selectively: creating the sH-LSP based on determining that the existingsH-LSP is not available to be used on the portion of the LSP, the sH-LSPbeing created based on the attribute information, or identifying thatthe existing sH-LSP is to be used on the portion of the LSP based ondetermining that the existing sH-LSP is available; and providing, by thedevice, an identifier associated with the created sH-LSP or anidentifier associated with the existing sH-LSP, the identifier beingprovided to permit the LSP to be set up based on the identifier.
 16. Themethod of claim 15, where determining whether the existing sH-LSP isavailable to be used on the portion of the LSP comprises: identifying anend of the existing sH-LSP; and determining whether the existing sH-LSPis available based on whether the end of the existing sH-LSP matches anend of the portion of the LSP.
 17. The method of claim 15, wheredetermining whether the existing sH-LSP is available to be used on theportion of the LSP comprises: identifying one or more configurations ofthe existing sH-LSP; and determining whether the existing sH-LSP isavailable based on whether the one or more configurations of theexisting sH-LSP match one or more corresponding configurations includedin the attribute information.
 18. The method of claim 15, wheredetermining whether the existing sH-LSP is available to be used on theportion of the LSP comprises: determining usage information associatedwith the existing sH-LSP; and determining whether the existing sH-LSP isavailable based on the usage information associated with the existingsH-LSP.
 19. The method of claim 15, where the identifier associated withthe created sH-LSP or the existing sH-LSP includes a Traffic Engineering(TE) link identifier.
 20. The method of claim 15, further comprising:determining that the sH-LSP is not being used to transfer trafficassociated with the LSP; and tearing down the sH-LSP based ondetermining that the sH-LSP is not being used to transfer trafficassociated with the LSP.